Delayed shutoff for headlights?

[ETAftw]

My ‘86 325e headlights stayed on when I turned off the switch today, had never done that before. Car was off. I cycled the switch on and off several times to no avail. I finally set about unplugging the battery so it would t drain and at some point while rousing up a wrench, the lights had turned off. Anyone had this happen? Failing relay perhaps?

Also, am I safe to assume an e30 will come back to life without any issues if I do end up needing to disconnect the battery at some point? (My e82 would throw a fit)

[bluptgm3]

Your E30 should be fine.


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[ETAftw]

Update, the headlights came on the next time I drove the car, but when I got home they were off despite still being switched on. (its a foggy day, so i didn't notice until i pulled into the garage, have no idea when they actually turned off.)

I swapped the relay with the horn relay after verifying that the horn works. with the relays swapped into the other position, the horn still works and the lights no longer work. If it was the switch, I don't see how they could have stayed on as described in my original post.

Any ideas?

[ETAftw]

Update #2:
Interesting. Since I bought the car in June, the headlights would always stay on if switched on, even when the car was fully off, keys out of the ignition. Considering this is how many older cars worked, I didn't think anything of it. Today, the initial issue was that they stayed on even when the car was off and the lights were switched off (pull switch fully pushed in). They eventually shut off as described in OP.

Then came drive #2 when they had turned off while driving, and wouldn't come on even with swapping relays around. I turned the ignition on to test the horn, but turned it back off before swapping relays, so I never tested it with the ignition on, didn't think I had to.

After my last post, I was doing some more reading on forums and eventually discovered that e30 headlights should turn off when the car is off, to save the battery, which is good. I just went back out to the garage and tried turning them on with the ignition on and sure enough they come on properly and all controls work correctly, low beam, hi beam, low beam flash works even when switch is off. They turned off as soon as I turned the ignition off. So the behavior seems to be back to what is normal for the car after playing around with the relays. I'll avoid driving at night for a while until I figure out if this is going to be an ongoing gremlin.

[ELVA164]

Either your switch is going bad or somebody messed with your wiring. There's nothing else in the circuit that could cause that, at least not that I'm aware of.

[ETAftw]

Agreed and thank you!

The relay definitely works. I’ll have to check the switch. Could a failing headlight switch (pull switch on dash) effect the automatic shutoff when ignition is off, or should I also investigate the main ignition?

[Irwie'C]

Could be that the switch itself is shorted. According to wiring schematics, Fuse 22&23 has a constant 12 volts going directly to the switch. So it could be the case for headlights to stay on when the ignition's off. Also check the wiring going from relays to the switch.